Version:            (using KDE 4.0.98)
Installed from:    Compiled From Sources
Compiler:          gcc 4.2.3 
OS:                Linux

I just converted my previous KDE 3 installation to KDE 4. After entering my KWallet password for my Mail accounts in KMail, the program crashes.
I traced this back in the source and it is most likely a problem with the POP Filter, which I activated in the KDE 3 version of KMail.

When checking the command line output from KMail, I always see a filter status of PopFilterAction = Down. The Down Action does not set the dlgPopup variable to true, so the mPopFilterConfirmationDialog is never created. And when the program tries to execute mPopFilterConfirmationDialog->result() afterwards it is quite normal that the program crashes.

Attached is the backtrace:
Anwendung: KMail (kmail), Signal SIGSEGV
Using host libthread_db library "/lib/libthread_db.so.1".
[Thread debugging using libthread_db enabled]
[New Thread 0xb47256d0 (LWP 2398)]
[KCrash handler]
#6  0xb56efe66 in QDialog::result (this=0x0) at dialogs/qdialog.cpp:383
#7  0xb7d6384a in KMail::PopAccount::slotJobFinished (this=0xa1c01e0)
    at /home/kde-devel/kde/src/kdepim/kmail/popaccount.cpp:619
#8  0xb7d65268 in KMail::PopAccount::slotResult (this=0xa1c01e0)
    at /home/kde-devel/kde/src/kdepim/kmail/popaccount.cpp:1060
#9  0xb7d66bb8 in KMail::PopAccount::qt_metacall (this=0xa1c01e0,
    _c=QMetaObject::InvokeMetaMethod, _id=4, _a=0xbf8b73ac)
    at /home/kde-devel/kde/build/kdepim/kmail/popaccount.moc:85
#10 0xb636e279 in QMetaObject::activate (sender=0xa53b518,
    from_signal_index=7, to_signal_index=7, argv=0xbf8b73ac)
    at kernel/qobject.cpp:3001
#11 0xb636ea32 in QMetaObject::activate (sender=0xa53b518, m=0xb6694868,
    local_signal_index=3, argv=0xbf8b73ac) at kernel/qobject.cpp:3071
#12 0xb659c743 in KJob::result (this=0xa53b518, _t1=0xa53b518)
    at /home/kde-devel/kde/build/kdelibs/kdecore/kjob.moc:186
#13 0xb659cc52 in KJob::emitResult (this=0xa53b518)
    at /home/kde-devel/kde/src/kdelibs/kdecore/jobs/kjob.cpp:290
#14 0xb6ba7a1f in KIO::SimpleJob::slotFinished (this=0xa53b518)
    at /home/kde-devel/kde/src/kdelibs/kio/kio/job.cpp:498
#15 0xb6ba8060 in KIO::TransferJob::slotFinished (this=0xa53b518)
    at /home/kde-devel/kde/src/kdelibs/kio/kio/job.cpp:967
#16 0xb6bae856 in KIO::TransferJob::qt_metacall (this=0xa53b518,
    _c=QMetaObject::InvokeMetaMethod, _id=7, _a=0xbf8b7608)
    at /home/kde-devel/kde/build/kdelibs/kio/jobclasses.moc:336
#17 0xb636e279 in QMetaObject::activate (sender=0xa5ed828,
    from_signal_index=8, to_signal_index=8, argv=0x0)
    at kernel/qobject.cpp:3001
#18 0xb636ea32 in QMetaObject::activate (sender=0xa5ed828, m=0xb6d05664,
    local_signal_index=4, argv=0x0) at kernel/qobject.cpp:3071
#19 0xb6c482f7 in KIO::SlaveInterface::finished (this=0xa5ed828)
    at /home/kde-devel/kde/build/kdelibs/kio/slaveinterface.moc:161
#20 0xb6c4a4c9 in KIO::SlaveInterface::dispatch (this=0xa5ed828, _cmd=104,
    rawdata=@0xbf8b77a4)
    at /home/kde-devel/kde/src/kdelibs/kio/kio/slaveinterface.cpp:175
#21 0xb6c4a90b in KIO::SlaveInterface::dispatch (this=0xa5ed828)
    at /home/kde-devel/kde/src/kdelibs/kio/kio/slaveinterface.cpp:90
#22 0xb6c3d4d7 in KIO::Slave::gotInput (this=0xa5ed828)
    at /home/kde-devel/kde/src/kdelibs/kio/kio/slave.cpp:319
#23 0xb6c3e8ab in KIO::Slave::qt_metacall (this=0xa5ed828,
    _c=QMetaObject::InvokeMetaMethod, _id=2, _a=0xbf8b78b8)
    at /home/kde-devel/kde/build/kdelibs/kio/slave.moc:75
#24 0xb636e279 in QMetaObject::activate (sender=0xa5eeab8,
    from_signal_index=4, to_signal_index=4, argv=0x0)
    at kernel/qobject.cpp:3001
#25 0xb636ea32 in QMetaObject::activate (sender=0xa5eeab8, m=0xb6d022c0,
    local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3071
#26 0xb6b7b137 in KIO::Connection::readyRead (this=0xa5eeab8)
    at /home/kde-devel/kde/build/kdelibs/kio/connection.moc:84
#27 0xb6b7bf48 in KIO::ConnectionPrivate::dequeue (this=0xa5eeb20)
    at /home/kde-devel/kde/src/kdelibs/kio/kio/connection.cpp:82
#28 0xb6b7cd7e in KIO::Connection::qt_metacall (this=0xa5eeab8,
    _c=QMetaObject::InvokeMetaMethod, _id=1, _a=0xa5ed818)
    at /home/kde-devel/kde/build/kdelibs/kio/connection.moc:72
#29 0xb6367c6b in QMetaCallEvent::placeMetaCall (this=0xa72cfe0,
    object=0xa5eeab8) at kernel/qobject.cpp:535
#30 0xb636a499 in QObject::event (this=0xa5eeab8, e=0xa72cfe0)
    at kernel/qobject.cpp:1131
#31 0xb5241ab3 in QApplicationPrivate::notify_helper (this=0xa05a070,
    receiver=0xa5eeab8, e=0xa72cfe0) at kernel/qapplication.cpp:3772
#32 0xb5246af5 in QApplication::notify (this=0xbf8b8148, receiver=0xa5eeab8,
    e=0xa72cfe0) at kernel/qapplication.cpp:3366
#33 0xb6951c93 in KApplication::notify (this=0xbf8b8148, receiver=0xa5eeab8,
    event=0xa72cfe0)
    at /home/kde-devel/kde/src/kdelibs/kdeui/kernel/kapplication.cpp:311
#34 0xb6357c66 in QCoreApplication::notifyInternal (this=0xbf8b8148,
    receiver=0xa5eeab8, event=0xa72cfe0) at kernel/qcoreapplication.cpp:587
#35 0xb6359097 in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0,
    event_type=0, data=0xa02a828)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#36 0xb635935d in QCoreApplication::sendPostedEvents (receiver=0x0,
    event_type=0) at kernel/qcoreapplication.cpp:1091
#37 0xb6386e4f in postEventSourceDispatch (s=0xa05c710)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:220
#38 0xb4a0f135 in IA__g_main_context_dispatch (context=0xa05c690)
    at gmain.c:2012
#39 0xb4a124e3 in g_main_context_iterate (context=0xa05c690, block=1,
    dispatch=1, self=0xa059760) at gmain.c:2645
#40 0xb4a12a8e in IA__g_main_context_iteration (context=0xa05c690, may_block=1)
    at gmain.c:2708
#41 0xb6387428 in QEventDispatcherGlib::processEvents (this=0xa038e58,
    flags=@0xbf8b7fa8) at kernel/qeventdispatcher_glib.cpp:325
#42 0xb52db7d5 in QGuiEventDispatcherGlib::processEvents (this=0xa038e58,
    flags=@0xbf8b7fd8) at kernel/qguieventdispatcher_glib.cpp:204
#43 0xb6356ddd in QEventLoop::processEvents (this=0xbf8b8050,
    flags=@0xbf8b8014) at kernel/qeventloop.cpp:149
#44 0xb6356f70 in QEventLoop::exec (this=0xbf8b8050, flags=@0xbf8b8058)
    at kernel/qeventloop.cpp:200
#45 0xb635941d in QCoreApplication::exec () at kernel/qcoreapplication.cpp:845
#46 0xb5241687 in QApplication::exec () at kernel/qapplication.cpp:3304
#47 0x0804aa9f in main (argc=174823432, argv=0x0)
    at /home/kde-devel/kde/src/kdepim/kmail/main.cpp:146
#0  0xb809c424 in __kernel_vsyscall ()